The ornamental design for an exteriorsurfaceconfiguration for a fuel tank, as shown and described.
FIG. 1 is a top perspective view of an exterior surface configuration for a fuel tank showing my new design;
FIG. 2 is a bottom perspective view of the exterior surface configuration for a fuel tank shown in FIG. 1;
FIG. 3 is a front view of the exterior surface configuration for a fuel tank shown in FIG. 1;
FIG. 4 is a rear view of the exterior surface configuration for a fuel tank shown in FIG. 1;
FIG. 5 is a right side view of the exterior surface configuration for a fuel tank shown in FIG. 1;
FIG. 6 is a left side view of the exterior surface configuration for a fuel tank shown in FIG. 1;
FIG. 7 is a top view of the exterior surface configuration for a fuel tank shown in FIG. 1; and,
FIG. 8 is a bottom view of the exterior surface configuration for a fuel tank shown in FIG. 1.
The broken lines shown in the figures represent portions of the exterior surface configuration for a fuel tank that form no part of the claimed design.